1. Field of the Invention
The present invention, in general, relates to apparatus which mount atop an existing oil well head and, more particularly, to systems which clean pipe, rod, and cable being extracted from oil wells.
During drilling of an oil well, drills strings and the like are periodically removed from the well. Devices which clean the oil off of the drill strings are known. These devices for cleaning oil wells during drilling of the well support the weight of the drill string that is being extracted by the equipment that is used for drilling the well. The equipment for drilling oil wells and for support of cleaning devices during drilling are commonly referred to as Overhead Rotary Tables.
Existing oil wells periodically require servicing which may include making repairs to pump motors and the like. Also for many other reasons the pipe, electrical cable, or rods which enter into the well must periodically be extracted. During this servicing the pipe and electrical cable which may be present in the oil well must be extracted. For certain other types of oil wells, an overhead "beam" type of pump transfers power into the well by a series of "rods" which are joined together and which must also be extracted periodically. It is preferable to remove the oil from these extracted components so that the oil does not pollute the ground. Ideally the oil is best removed from the devices so that it reenters the oil well itself.
Know prior types of devices for cleaning the pipe and electrical cable of existing oil wells rely upon rubber types of wipers which squeegee some of the oil off of the pipe and cable as it is being extracted from the well. However these devices fail to remove much of the oil that is present on the "string" that is being extracted.
There is no known way of extracting the oil and flushing it back into the well by utilizing a device which both is capable of bearing the weight of the pipe and cable (known as the "production string") or the weight of the rod (known as the "rod string") being extracted and which is also capable of flushing the oil back into the well.
Accordingly there exists today a need for an oil well head cleaning system that can support the weight of the pipe and cable or rod that is being extracted and which is able to flush a significant quantity of oil off of the extracted string.
2. Description of Prior Art
Oil drill string cleaning systems are, in general, known. For example, the following patents describe various types of these devices:
U.S. Pat. No. 1,038,231 to Taylor & Wolfe, Sep. 10, 1912;
U.S. Pat. No. 2,514,817 to Wheaton et al, Jul. 11, 1950;
U.S. Pat. No. 2,611,146 to Buckley, Sep. 23, 1952;
U.S. Pat. No. 2,620,504 to Slater, Dec. 9, 1952;
U.S. Pat. No. 2,914,786 to Hunt, Dec. 1, 1959;
U.S. Pat. No. 3,071,796 to Waldrop, Jan. 8, 1963;
U.S. Pat. No. 3,475,781 to Grant, Nov. 4, 1969;
U.S. Pat. No. 3,626,540 to Rood, Dec. 14, 1971;
U.S. Pat. No. 3,822,753 to Tate, Jul. 9, 1974;
U.S. Pat. No. 4,399,869 to Bentley, , 19;
U.S. Pat. No. 4,895,205 to Thompson et al, Jan. 23, 1990;
U.S. Pat. No. 5,101,896 to Thompson et al, Apr. 7, 1992; and
U.S. Pat. No. 5,217,069 to Badon, Jun. 8, 1993.
While the structural arrangements of the above described devices, at first appearance, have similarities with the present invention, they differ in material respects. These differences, which will be described in more detail hereinafter, are essential for the effective use of the invention and which admit of the advantages that are not available with the prior devices.